BARCELONA (Reuters) - Nico Rosberg boosted his morale by keeping Mercedes team- mate and championship leader Lewis Hamilton off the top of the timesheets in first practice for the Spanish Grand Prix on Friday.

He registered a best lap of one minute, 26.828 seconds, 0.070 quicker than Hamilton, on a sunny morning at the Circuit de Catalunya as the sport kicked off its first European weekend of the season.

Hamilton, last year's winner in Spain, has won three of four races this season and started all on pole. He leads Rosberg by 27 points.

Ferrari's Sebastian Vettel was third fastest, but with a time of 1:27.806, that underlined the gap to make up on Mercedes, with team-mate Kimi Raikkonen fourth in a predictable looking leaderboard.